Headteacher Pauline Washington has every reason to be thrilled. She's been waiting for the Cooking Bus to visit her infant school for five long years; a whole lifetime for the children, who press their faces through the gaps in the school fence to watch its approach.

At first sight the vehicle looks like any other 19-tonne articulated lorry, but once parked in the playground of Montgomerie infant school in Benfleet, Essex, driver Stuart Brooks works his magic, extending its sides to reveal a state-of-the-art mobile kitchen.

On board the bus the next morning, the children can scarcely believe their eyes. "It's so big," says Ben, four, as he struggles into his apron. "This is the first time I've done cooking." Two food technology teachers, Jane Sixsmith and Michaela Bowles, lead the children through a 75-minute session making crab cakes, tropical fruit kebabs and fruit smoothies.

The children learn how to hold their hands like an animal's claw so they can grip fruit to cut it, how to find a "best before" date on an egg and how to mash potato and crab. They learn the names of ingredients and the importance of tasting and smelling as you cook.

Sixsmith reminds the children of the five-a-day healthy eating message they've heard at school and they all hold up five fingers. But when Ella, four, volunteers the information that fruit is healthy, her mother, Tracey, laughs. "Shame she doesn't eat it," she mutters, as she helps with the washing up.

This scene on the bus reflects what's taking place across Britain. While there's hope for the future food education of these children, a whole generation has passed through the school system without learning how to cook and look after themselves nutritionally. Bowles recalls a mother in her 20s who approached the Cooking Bus in Preston: "She was absolutely desperate. She'd heard all these healthy messages like five a day, she knew what to eat, but she totally lacked the skills to feed herself and her child."

Food culture

"It's disgusting we're in this state," says Anita Cormac, director of the Focus on Food campaign, which operates the Cooking Bus. "There's been a whole erosion of food culture in our schools. Every child should have a right to a food education; it's only if you can cook that you have a choice in what you eat."

Cormac dreamed up the idea of the Cooking Bus after a career as a food technology teacher in secondary schools in London. She approached the Royal Society for the Encouragement of Arts to back her plan, and secured funding to commission the first bus. She has been struggling to cope with the demand ever since.

The original Cooking Bus hit the road in 1998 and worked with more than 60,000 children and teachers before it retired. This second bus is sponsored by the Food Standards Agency and visits 42 primary and secondary schools a year. Sixsmith and Bowles have been on board for more than two years now, and have assessed at first hand the state of food education Britain's schools.

"Anything long and green - leeks, courgettes - is a cucumber to the children," says Sixsmith. Children are often shocked when shown a vegetable still covered in soil. In one school she showed nine-year olds some tuna fish and asked them what it was. "Donkey," one replied - and not a single child laughed.

They've travelled to schools in impoverished areas where food knowledge is good, and middle-class schools where the children eat poorly. Overall the picture is of children disconnected from food.

So what happened to food education? "It's only in the last four to five years that 'cooking' has become an acceptable word again," explains Roger Standen, of the Focus on Food campaign. "When the national curriculum was being piloted, food was in danger of being written out."

Standen and Cormac campaigned to ensure cookery was included in the design and technology curriculum, but it was made compulsory only for primary schools. The dogma of technology dominated. Children's work concerned design, packaging and manufacture, rather than food itself.

Back on the Cooking Bus, the teachers at Montgomerie infant school are having their own workshop, going through which equipment is best to use with children and food preparation techniques.

Washington laughs at the hopelessness of her pastry folding, as the staff make samosas to take home. Her mood darkens, however, when she is asked about how schools are coping with the current deluge of healthy living initiatives. There are guidelines on healthy school status; an inspection requirement relating to the Every Child Matters white paper; pilot projects; toolkits. "It's one after another," she says. "When we go on courses, teacher morale is actually quite low. They're thinking, 'If we're not doing this, we're going to get found out by Ofsted'."

More buses

The government has announced plans to bring cookery lessons back to secondary schools. Cormac aims to build more Cooking Buses and visit more schools.

As the staff travel home from Montgomerie infant school that night, Brooks, the truck driver is preparing for a night's rest in the school playground. He locks up the Cooking Bus and climbs up into his cab. "I chased up and down motorways and around Europe for 25 years," he says. "But I've enjoyed every minute of this job."